Rick Santorum’s campaign accused Mitt Romney of “dirty politics” after the Michigan Republican Party credentials committee voted to award both of the state’s at-large delegates to Romney, which advisers say was the result of changing the rules after the votes were counted.

Romney came away with 16 of the state’s 30 delegates, while early projections showed Romney and Santorum tied at 15 delegates apiece.

“I think this is a very sad commentary on the Romney campaign — that for one delegate they would break the rules, and risk tearing the state party apart for one delegate,” said Ohio Attorney General Mike DeWine, who previously backed Romney.

Santorum adviser John Brabender said something like the rule change doesn’t happen in the United States, “maybe in Iran or other countries.”

“It is dirty politics, it is dirty tricks,” DeWine added.

The campaign sent a letter to the Republican National Committee asking them to investigate the issue, but has not planned legal action as of yet.

Saul Anuzis, the Republican National Committeeman from Michigan and a Romney endorser, explained in the blog post that the explanation of the rules passed by the credentials committee on February 4th was incorrect, and that the committee always intended for the at-large delegates to be given to the winner of the popular vote.

The Santorum campaign rejected that explanation, alleging that members of the committee were in the tank for Romney — even if they haven’t formally endorsed him.

Romney spokesperson Andrea Saul fired back at Santorum, repeating their charge that Santorum tried to “hijack” the process by recruiting Democrats into the race.

“Rick Santorum encouraged Democrats in Michigan to hijack the Republican Primary,” she said. “Because his strategy failed and Mitt Romney won, he is now attacking the Republican Party. The Romney campaign respects the process as determined by the Michigan state party, and we are pleased that we have been awarded a majority of the delegates. We are now focused on the upcoming contests.”